Exciton–plasmon coupling and light field manipulation within perovskite quantum dot-decorated aluminum metasurfaces

To advance the development of quantum modulator, it is essential to enhance the light–matter interactions through coupling between quantum dots (QDs) and metallic plasmonic nanostructures. In this work, efficient tuning of the emission properties of CsPbBr3 QDs in the visible region is demonstrated by coupling the QDs to a plasmonic metasurface that supports the polarization and phase control of light. We design the Pancharatnam–Berry phase metasurfaces, which ensure that each unit nanostructure can couple with the QDs and regulate the responses on demand. By tuning the geometry of the plasmonic nanostructure array, controllable shaping of the emission spectra from QDs is achieved, selectively enhancing specific wavelength ranges across the emission spectrum. The enhancement and shaping of the emission spectrum can be attributed to the Purcell effect, which is corroborated by systematic measurements, such as radiative lifetimes. Moreover, coupling of the CsPbBr3 excitons and the metasurface’s plasmons further improves the photoluminescence emission and realizes the spectrum and phase modulations of the emission. Our work may prompt the development of high-speed photonic modulators or high-efficiency quantum light sources based on perovskite QDs and plasmonic metasurfaces.